This invention relates to turbine engines. In particular, the invention relates to multiple-fluid, multiple-substance, multiple-phase, multiple-pressure, multiple-temperature, and/or multiple-stage turbine engines and to systems and methods that incorporate or use them.
Background art steam turbine, water turbine and gas turbine designs have been known for decades. Numerous attempts have been made at enhancing current designs, improving efficiencies, decreasing maintenance, and decreasing manufacturing and installation costs. Many of these designs and attempts have focused on devices capable of using inlet fluid(s) which is/are often relatively high pressure and/or high temperature and in a vaporous condition to avoid component damage, with some designs focused on lower pressure and/or temperatures associated with by-product, or waste, streams for the inlet fluid(s). Even designs which focus on two-phase inlet fluids often fall short of accomplishing the intended goal, especially in the areas of costs associated with manufacturing, installation and, especially, operation and maintenance. In addition to steam, liquid water, air, natural gas, fuel oil and geothermal fluid being used for some applications, other substances or elements, such as nitrogen, oxygen, hydrogen, argon or engine exhaust, to name a few, are/may be used as inlet fluid(s).
A background art design for these turbines incorporates one or more stages, wherein a stage is comprised, in general, of a stationary element and a rotating element. The stationary element of a stage functions principally as either a nozzle or a means of redirecting the direction of flow of the fluid entering the element. Typically, for the first stage, the stationary element functions as a nozzle; for subsequent stages, if any, the stationary element can function in capacity, nozzling, redirecting, or a combination thereof. The rotating element functions principally as the recipient of high velocity fluid directed to impart rotary motion to the turbine (rotor), but can, on larger turbines, also function in a nozzle capacity, as a reaction blade versus an impulse blade. For turbines incorporating two or more stages, the staging classification is generally designated as either velocity-compound or pressure-compound. Turbines can have either velocity-compound sections or pressure-compound sections or a combination thereof.
For velocity-compound sections, the stationary element of the first stage of a velocity-compound section functions principally as a nozzle to increase the velocity of the fluid exiting from the nozzle, while the stationary element of the following stages principally function only to redirect the fluid path to the optimal direction for the associated rotating element(s). The fluid exiting a nozzle has a potential to develop mechanical work and/or power from the turbine. With velocity-compounding, this fluid velocity potential is essentially divided amongst the number of stages. Noteworthy, the pressure drop across the stationary elements of the second or more stages is ideally nil, but, realistically, a small pressure drop is caused essentially by friction and a relatively small transfer of heat.
In contrast, for pressure-compound sections, the pressure drop across the stationary elements of the second or more stages is designed to decrease, not remain ideally zero. This feature, in turn, increases the fluid velocity exiting the stationary element and entering the rotating element of each stage. With pressure-compounding, the fluid pressure potential is essentially divided amongst a number of stages, wherein the velocity potential exiting each nozzle is ideally converted into its maximum work potential before entering the next stationary element (nozzle). Pressure-compounding in turbines is especially suited for, but not limited to, inlet fluids of higher pressures, as the pressure drop per stage is less across more than one stage and, thus, increases turbine efficiency and turbine mechanical work or output energy. While some turbines are designed essentially as a velocity-compound turbine or as a pressure-compound turbine, often turbines are designed to incorporate a combination of these features.
For approximately a century, background art turbine designs have illustrated many different arrangements of stationary and rotating elements, with each design attempting to increase turbine efficiency, decrease maintenance and turbine outages, decrease manufacturing costs and time, decrease the detrimental effects of a liquid fluid state existing or developing within the turbine, such as a background art steam turbine, or decrease the detrimental effects of a fluid condition of high temperature, such as a background art gas turbine. Due to concerns with the effects of a liquid fluid condition, especially for background art steam turbines, qualified operations personnel are almost universally used to operate steam turbine power facilities. Additionally, some other fluid applications for turbines also incorporate operations personnel for equipment and personnel safety, or for concerns with the effects of high temperature, as in the case of background art gas turbines used for stationary and mobile applications. Automatic controls and devices are used to reduce the potential for detrimental conditions to occur, but many facilities still incur the costs for operational personnel for reasons associated with good business practice, safety, and the potential for equipment failure.
Background art turbines are relatively expensive, owing to the close tolerances associated with their stages and seals, sophisticated materials applicable to the high pressure and high temperatures of the turbine inlet fluid, complex arrangements of stages and associated components, internal cooling capacities and apparatus, structural support system for the turbine rotor(s) and/or rotor section(s), and the need for ancillary support and systems, all of which are designed to provide long, non-destructive life to the turbine and enhance its efficiency. Thus, operators protect the investment in the turbine by taking appropriate actions in the event of malfunctions or unsatisfactory operating parameters and conditions. The costs associated with operators and maintenance personnel are not insignificant.
When a turbine is incorporated into a power generation facility, a significant portion of the annual facility expense is associated with the operational requirements of the turbine. For a facility using a turbine that can operate using a turbine inlet fluid in either a liquid state or vapor state, or both, i.e., multiple-phase, the operational requirements compared to those of a background art turbine are reduced or eliminated. Such reduction or elimination significantly decreases the facility's expenses. Additionally, a turbine that is mechanically sound when operated on either liquid or vapor can be easily sized to match the requirements of its customer, whether very large or very small. Likewise, a turbine that can use more than one inlet fluid at a time can serve a multiple purpose in one machine, as opposed to using a separate turbine for each fluid.
For a background art gas turbine or combustion turbine, the temperature of the fluid in the combustion chamber or liner section(s) must be controlled so as to be compatible with the physical configuration and metallurgical properties of the materials of construction. Often cooling air or another cooling medium is directed in and about the combustion process to affect the physical location of the combustion process in the combustion chamber or liner section(s) and accompanying areas of hot gases and/or to affect the temperature of the combustion fluid that contacts the material. The fluid exiting the combustion chamber or liner section(s) enters the turbine section and associated stages. The temperature of the fluid entering the turbine section, commonly called the turbine inlet temperature (TIT), is managed at a temperature that is physically and metallurgically compatible with the configuration and materials of construction of the turbine, in particular, the first stage nozzles. In general, for a background art gas turbine or combustion turbine, the combustion fluid is cooled to a turbine inlet temperature in the low-to-mid 2,000 degree Fahrenheit (F) range. Thus, enormous quantities of cooling medium are used to bring the combustion temperature down to approximately 2,000+ degrees F.
The background art is characterized by U.S. Pat. Nos. 593,219; 709,242; 753,735; 768,884; 999,776; 1,065,985; 1,110,302; 1,681,607; 1,880,747; 2,346,936; 3,026,088; 3,758,223; 3,879,152; 3,938,336; 4,003,673; 4,030,856; 4,336,039; 4,441,322; 4,452,566; 4,453,885; 4,682,729; and 6,533,539; and U.S. Patent Application No. 2004/0005214; the disclosures of which patents and patent application are incorporated by reference as if fully set forth herein.
House in U.S. Pat. No. 593,219 discloses a rotary engine which utilizes a significant portion of the steam velocity energy exiting peripheral nozzles to induce air into the discharge stream of the steam nozzle. The inventor claims the air provides a substance (“surface”) upon which the steam velocity can react to provide rotary motion to the rotor. Such entrance of air significantly reduces the efficiency of the turbine. The discharge of steam, and air, can be either along the peripheral surface of the rotor or the sides of the rotor; however, the efficiency of the engine is greatly compromised.
Gill in U.S. Pat. No. 999,776 discloses a reaction engine that purposely reduces the otherwise available tangential reactionary force to reduce what was believed, at the time, to be an impractical engine speed. This device incorporates nozzles that are rotatable 180 degrees so as to reverse the direction of rotation by rotating the nozzles about a radial axis. The inefficiencies associated with the reduced pressure are not recovered with the claimed advantage of reduced speed.
Eskeli in U.S. Pat. No. 3,758,223 discloses a reaction type turbine rotor, with a stationary feeder for reducing a supply pressure and increasing the exit velocity of stationary nozzles, which essentially mirrors a background art axial-flow steam turbine device that uses a stationary inlet nozzle assembly and imparts the increased velocity to rotate a turbine rotor. In the device of Eskeli, this process is accomplished in essentially a radial direction while the process occurs essentially in an axial direction for a background art steam turbine. The device of Eskeli is designed only for use of liquids or vapors. Thus, it is not designed to be used with a mixture of vapor and liquid.
Eskeli in U.S. Pat. No. 3,879,152 discloses a method and apparatus for generation of power in response to a fluid flowing from a higher pressure to a lower pressure in rotating reaction turbine. The higher pressure fluid is let down (reduced) to establish a velocity of sufficient direction and magnitude to be greater than the rotating fluid inside a reaction turbine rotor. The lower pressure fluid inside said rotor is then increased due to centrifugal force, wherein the centrifugal force becomes a parasitic load and subtracts from the net power output, thus reducing an otherwise higher claimed efficiency. Additionally, the device is designed for use of either liquid or vapor, but not simultaneously both or a combination thereof.
Eskeli in U.S. Pat. No. 4,030,856 discloses essentially a liquid pump and pump discharge throttle (external to pump casing) combination in one housing, as opposed to two separate entities.
Sohre in U.S. Pat. No. 4,336,039 discloses a turbine that converts radial fluid flow into tangential velocity to produce work. His invention is a reaction radial outflow turbine (a refinement of the basic Hero engine) that requires no stator nozzles, having contoured supersonic nozzles near the periphery of the turbine rotor. Such contoured nozzles provide a substantial, but not nearly complete, tangential velocity to the steam leaving the nozzle.
Ritzi in U.S. Pat. No. 4,441,322 discloses a device which separates a two-phase, inlet fluid (vapor and liquid) into a vapor stream and a liquid stream, each of which is used to produce rotary motion of a turbine rotor. For two-phase fluids, such as geothermal fluids and some waste fluids, contaminates can cause severe imbalance of the rotating drum and potentially cause blockage of the liquid exit nozzles of the rotor, thus, causing mechanical damage or inefficient operation.
Denton in U.S. Pat. No. 4,453,885 discloses a device with counter-rotating jets generally, but not specifically, oriented in a tangential direction. This causes the device to have uneven torque/power transmission.